Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 222208 AFDLWX Area Forecast Discussion National Weather Service Baltimore MD/Washington DC 608 PM EDT Sat Oct 22 2016 .SYNOPSIS... Surface high pressure will build south of the area through the remainder of the weekend as low pressure pulls lifts north from New England. A reinforcing cold front will move through Monday with cool high pressure to follow for mid week. A low pressure system will approach from the west late in the week. && .NEAR TERM /THROUGH SUNDAY/... Was able to drop the wind advisory per observations. It will remain quite gusty into the overnight as the pressure gradient remains high. However, cold air advection is tapering off at 850mb and 925mb per GFS/ECMWF, so gusts should continue to slowly decrease. Radar trend is for a continued eastward shift in the plume off Lake Erie with further sprinkles most likely KHGR and east. Min temps around 40F inland, mid 30s near shore. Low 30s limited to the highest ridgelines, not of any known agricultural significance, so no freeze warning tonight. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/... Main trough axis lifts to the northwest for Sunday and Sunday night which will allow for dry weather. Since we will still be in the gradient with low pressure to the NE and high pressure to the SW, it will still be breezy with 20-35 MPH gusts during the day. Under weak warm advection, temperatures should recover 5-8 degrees. A reinforcing cold front will drop south into the area on Monday. It will be moisture starved though, with only a small chance of showers in the highlands. High temperatures will depend on the timing of frontal passage, with southern areas standing the best chance to see highs reach the 70+. The wind will still be noticeable as well with gusts of 20-30 MPH. High pressure will build from the west Monday night with lows returning to the 30s and 40s. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Long term starts out with a big closed low over Atlantic Canada and fast northwest flow on its southwestern flank over our region. This low will very slowly shift east out into the Atlantic so that by early Thursday a weak ridge is located over our region. This will quickly be followed by a sharp trough which will move in Thursday night. After that uncertainty grows with some guidance pushing the shortwave through but leaving the longwave trough in place...while other guidance cuts off a deep low over the region aloft. For our sensible weather at the surface, this translates to high pressure slowly building in with diminishing northwest winds Tuesday. While the surface high doesn`t build directly overhead, it will be close enough such that we could have a good radiational night on Tuesday night, perhaps enough to bring frost into suburbs again. High pressure remains to our north influencing our weather on Wednesday into Wednesday night, but by Thursday, the next surface low pressure will be approaching from the west with increasing clouds and rain chances. Depending on the progress of the system, the rain may continue into Friday or even Friday night, or end fairly quickly. This is still pretty uncertain. Overall, temps will stay below normal, with the coolest period likely Tuesday with a little warming possible just ahead of the front on Thursday. && .AVIATION /22Z SATURDAY THROUGH THURSDAY/... VFR conds continue into midweek. NW gusts to 30 kt into this evening, slowly easing overnight. Westerly gusts of 20-30 kt are expected on Sunday. Otherwise, only some cumulus clouds around FL050. A cold front will pass through Monday, with winds becoming NW again with gusts 20-25 kt. VFR overall Tuesday through Wednesday night outside of any early morning fog, which would mainly CHO/MRB/IAD. Sub-VFR cigs/vis possible Thursday on as a storm system brings rain back to the region. && .MARINE... NW gales extended until 8pm for far northern MD waters and allowed to drop for the middle/upper tidal potomac where an SCA is in effect. Gales drop at 2am for remaining waters and SCA for all waters through Sunday with 25 kt gusts expected. SCA for at least portions of the waters then Monday/Monday night. Overall looking like winds will diminish through Tuesday with sub- SCA likely by Tuesday night. Southerly channeling could bring winds back to SCA levels Wednesday night or Thursday, but this is still highly uncertain. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...None. MD...None. VA...None. WV...None. MARINE...Small Craft Advisory from 2 AM Sunday to 6 AM EDT Monday for ANZ531>534-537-539>541-543. Gale Warning until 2 AM EDT Sunday for ANZ531>534-537-539>541- 543. Small Craft Advisory until 6 AM EDT Monday for ANZ530-538. Gale Warning until 8 PM EDT this evening for ANZ530-538. Small Craft Advisory until 6 AM EDT Monday for ANZ542. Gale Warning until 6 PM EDT this evening for ANZ535-536-542. Small Craft Advisory until 6 PM EDT Sunday for ANZ535-536. && $$ SYNOPSIS...BAJ/ADS NEAR TERM...BAJ/ADS SHORT TERM...ADS LONG TERM...RCM AVIATION...BAJ/ADS/RCM MARINE...BAJ/ADS/RCM is the U.S. government's official web portal to all federal, state and local government web resources and services.